Co-molded components of a redox flow battery stack

ABSTRACT

A cell plate assembly of a redox flow battery has a frame body and a cell plate in fluidic communication. Cell plates, electrolyte pathways and other components of the frame plate assembly may be overmolded inside a frame. Plates, frames and tubes may all be robustly sealed. One piece bonded plug and frames enable reduced use of O-rings and other wear items.

INTRODUCTION

A rechargeable flow battery (e.g., a redox flow battery) stores chemicalenergy in electrolyte solutions that contain electro-active elements.Conversion of this chemical energy to electrical energy may be capturedand used to power a variety of devices and/or delivered to a power grid.

A typical rechargeable flow battery will have one or more cells. Thecell will have an anolyte solution portion and a catholyte solutionportion. These portions are separated by a membrane. Reservoirscontaining additional anolyte and catholyte solutions are fluidicallycoupled to the anolyte portion and catholyte portion of the cell,respectively. As each electrolyte solution is circulated through itsrespective portion of the cell, the membrane allows for proton exchangebetween the anolyte solution and the catholyte solution. A currentcollector (e.g., an electrode) transfers the energy associated with theelectron exchange between the anolyte and the catholyte to or from apower source depending on whether the redox-flow battery is beingcharged or discharged.

Current redox flow technology is limited by several issues. For example,maintenance of wear-parts, prevention of cross contamination ofelectrolyte solutions between cells (and between the portions of acell), and reduction of manufacturing costs continue to be challengingwith current redox flow technology.

It is with respect to these and other considerations that aspects of thetechnology have been disclosed. Also, although relatively specificproblems have been discussed, it should be understood that thetechnology disclosed herein should not be limited to solving thespecific problems identified in the background or the disclosure.

Redox Flow Battery

Aspects of the technology relate to a redox flow battery with a cellplate and a frame, which together form a frame plate assembly. Inembodiments, multiple frame plate assemblies are stacked together toform a cell stack. The cell plates are fluidically coupled to the frameof the frame plate assembly. Electrolyte pathways and other componentsof the frame plate assembly may be overmolded such that the componentsinside the frame. Additionally, plates, frames, and pathways may all berobustly sealed.

Methods of manufacture include over molding a cell plate and/or otherelements of the frame plate when molding the frame body. That is,component parts of a frame-plate assembly, may be disposed within aframe plate. Plastic injection molding or other techniques may be usedto form a mold around the cell plate (and other inserts, such as tubingfor electrolyte pathways and frame channel inserts). These and othermethods of manufacturing may result in the cell plate, electrolytetubing, and frame channels being disposed within the frame duringmolding.

These and various other features as well as advantages that characterizethe systems and methods described herein will be apparent from a readingof the following detailed description and a review of the associateddrawings. Additional features are set forth in the description whichfollows, and in part will be apparent from the description, or may belearned by practice of the technology. The benefits and features of thetechnology will be realized and attained by the structure particularlypointed out in the written description and claims hereof as well as theappended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exclusive embodiments are described with referenceto the following figures.

FIG. 1 illustrates an embodiment of a redox-flow battery system having acell stack.

FIG. 2 illustrates an exploded-perspective view of a cell stack system.

FIGS. 3A and 3B illustrate an example electrolyte pathway betweenmultiple frame plate assemblies of a redox cell stack.

FIG. 4 illustrates a perspective view of an example of a frame suitablefor co-molding.

FIG. 5 illustrates a view of a face of a co-molded frame plate assembly.

FIG. 6 illustrates a view of a face of a co-molded frame plate assemblywith electrolyte pathways.

FIG. 7 is a perspective view of a co-molded frame plate assembly frameplate assembly.

FIG. 8 illustrates a cross section view of a co-molded frame plateassembly.

FIG. 9 is an example process for forming a co-molded frame plateassembly

FIG. 10 illustrates four overmolded components in an arrangement forco-molding.

FIG. 11 illustrates an example result of an overmolding process.

FIG. 12 illustrates an example where the overmolding process includes acell plate.

FIG. 13 illustrates an exploded view of an embodiment of a frame plateassembly with various components that may be overmolded.

FIG. 14 illustrates various views of an embodiment of frame channelcomponent for overmolding.

FIGS. 15A-15D illustrate various views of an embodiment of a componentthat may be used in an over molding process.

FIGS. 16A-16D illustrate another example component that may be used inan over molding process.

DETAILED DESCRIPTION

Aspects of the technology relate to one or more of the components of aframe plate assembly co-molded within a frame. For example, cell plates,frame channels, electrolyte pathways, and other components may beco-molded with the frame.

Co-molding allows for, in aspects of the technology, a one-piececonfiguration that reduces the use of O-rings and other connection itemsthat wear down during use. These points of connection, which may notseal properly or may wear under normal battery operating conditions, maycause failure or reduce service life. For example, a cell plate of aredox flow assembly may be sealed, using the overmolding techniquesdescribed herein, to an electrolyte pathway rather than coupling to theelectrolyte pathway through the use of snap fit or other connectors. Inadditional/alternative embodiments, the electrolyte pathways and theframe channels may be integrated inside the frame using the overmoldingtechnique.

FIG. 1 illustrates an embodiment of a redox-flow battery system 100having a cell stack 102. As illustrated, redox-flow battery system 100also includes a catholyte reservoir 104 holding a catholyte solution1106 and an anolyte reservoir 108 holding an anolyte solution 110.Additionally, catholyte current collector 120 and anolyte currentcollector 122 are present, as is a first pumping mechanism 112 tocirculate the catholyte solution 116 from the catholyte reservoir 102 tothe cell stack 1102, and a second pumping mechanism 116 to circulate theanolyte solution 110 from the anolyte reservoir 108 to the cell stack102.

In an embodiment, the redox-flow battery system 100 may be one of avanadium-vanadium redox flow battery, a polysulfide bromide battery, aniron-chromium battery, or a manganese-vanadium redox flow battery. In anembodiment where the redox-flow battery system 100 is a vanadium redoxflow battery, the catholyte solution 106 is substantially V⁵⁺ in thecharged state. Additionally, where the battery is in the charged state,the anolyte solution 110 is substantially V²⁺. In an embodiment wherethe system is a polysulfide bromide battery, the catholyte solution 106is substantially sodium tribromide, and the anolyte solution 110 issubstantially sodium disulfide in a charged state. In an embodimentwhere the system is an iron-chromium battery, the catholyte solution 106is substantially Fe³⁺, and the anolyte solution 110 is substantiallyCr²⁺ in a charged state. In an embodiment where the system is amanganese-vanadium battery, the catholyte solution 106 is substantiallyMn³⁻, and the anolyte solution 110 is substantially Vn²⁺ in a chargedstate. It will be appreciated that the technologies described herein maybe used with other redox-flow battery chemistries.

A cell stack 102 may include a plurality of cell plates. Each cell plateof the cell stack 102 facilitates the exchange of electrical energybetween the catholyte and the electrolyte during a charge/dischargecycle. A cell plate, which includes a proton exchange membranepositioned between the two electrodes, allows the transfer of a protonfrom the catholyte to the anolyte during the discharge cycle, and acurrent collector facilitates the exchange of an electron from theanolyte to the catholyte during the discharge cycle. The cell stack 102may have cells that are in series or are in parallel. While only onecell stack 102 is illustrated, it will be appreciated that multiple cellstacks may be electrically coupled together in either series orparallel.

In an embodiment, one or more mechanical pumps are used as a firstpumping mechanism 112 and a second pumping mechanism 116 to circulatethe catholyte solution 106 and the anolyte solution 110, respectively.Other methods and/or equipment may be used to provide circulation of thecatholyte solution 106 between the catholyte reservoir 104 and the cellstack 102, as well as to circulate the anolyte solution 110 between theanolyte reservoir 108 and the cell stack 102.

As illustrated, the catholyte reservoir 104 is fluidically coupled tothe cell stack 102 by a catholyte pathway 114 (which may be a tube, apipe, or the like), and the anolyte reservoir 108 is fluidically coupledto the cell stack 102 by an anolyte pathway 118 (which may be a tube, apipe, or the like). It will be appreciated that one or more cell stacks102 may be configured to be fluidically coupled together in seriesand/or parallel.

FIG. 2 illustrates an exploded-perspective view of a cell stack system200. In aspects of the technology, cell stack system 200 includes aplurality of frame plate assemblies 201, which includes a first frameplate assembly 202, a second frame plate assembly 204, and a third frameplate assembly 206. As illustrated, each frame plate assembly, such asthe first frame plate assembly 202, the second frame plate assembly 204,and the third frame plate assembly 206, are rectangular prisms, thoughthey need not be.

It will be appreciated that each frame plate assembly has a front faceand a back face as described further below. For example, the first frameplate assembly 202 has a front face and a back face. In aspects of thetechnology, the front face and the back face are substantially planar.

In aspects of the technology, the back face of the first frame plateassembly 202 is disposed proximate to the front face of the second frameplate assembly 204, the back face of the second frame plate assembly 204is disposed proximate to the front face of the third frame plateassembly 206, and so on. A first frame plate assembly 202 includes, inembodiments, a frame and a cell plate (e.g., a monopolar or bipolarplate comprising carbon paper electrodes and a membrane), which cellplate is used to facilitate the charging/discharging of a redox flowbattery. Various embodiments of frame plate assembly are discussed infurther detail with reference to figures herein.

The plurality of frame plate assemblies 201 may be coupled togetherusing one or more framing members. For example, the back face of thefirst frame plate assembly 202 may be coupled to the front face of thesecond frame plate assembly 204 using one or more framing members, theback face of the second frame plate assembly 204 may be coupled to thefront face of the third frame plate assembly 206, and so on.

Coupling may occur through a variety of means. As illustrated, theplurality of frame plate assemblies 201 are coupled together usingframing rods 6 The framing rods 216 orthogonally penetrate the frontface and the back face of the first frame plate assembly 202. Theframing rod is a type of framing member. In aspects of the technology,the framing members may be rods, plates, walls, shafts, and/or any itemcapable of coupling each of the plurality of frame plate assemblies 201to adjacent frame plate assemblies. In aspects of the technology, thefirst frame plate assembly 202 has a plurality of bores operable toreceive the plurality of framing rods 218. Additionally, fasteners 218couple the framing rods 216 to the first frame plate assembly 202.Though the illustrated fasteners 218 are bolts that couple to a threadedend of the framing rods 216, it will be appreciated that other fasteningtechnology is contemplated.

Similarly, the second frame plate assembly 204 has a plurality of bores,which bores may be aligned with the bores of the first frame plateassembly 202 such that the plurality of framing rods 216 may bereceived. In alternative embodiments, other framing members may be used.The other frame plate assemblies in the plurality of frame plateassemblies 201 may have similarly aligned bores to receive the framingrods 216. As such, each frame plate assembly of the plurality of frameplate assemblies 201 may couple to the adjacent frames by sliding overthe framing rods 218.

As illustrated, the plurality of framing rods 216 may be secured to afirst mounting plate 212. The first mounting plate 212 may cap the topof the plurality of frame plate assemblies 201. That is, the firstmounting plate 212 may be disposed on the front side of the first frameplate assembly 202. Similarly, a second mounting plate 214 may cap alast frame plate assembly 216 of the plurality of frame plate assemblies201, the last frame plate assembly 216 being disposed at the oppositeend of the plurality of frame plate assemblies 201 from the first frameplate assembly 202.

Additionally illustrated in FIG. 2 is electrolyte piping 224 and 226.The electrolyte piping fluidically couples an electrolyte reservoir,such as an anolyte reservoir or catholyte reservoir, to the plurality offrame plate assemblies 201. As illustrated, the electrolyte piping 224and the electrolyte piping 226 penetrate through the first frame plateassembly 202 through an angle orthogonal to the front face and the backface. The electrolyte piping 224/226 may deliver and/or return theelectrolyte solution to each frame plate assembly in the plurality offrame plate assemblies 201.

The reservoirs may be the same as or similar to the electrolytereservoirs described with references to FIG. 1. In aspects of thetechnology, each frame plate assembly is designed with a pathway suchthat an electrolyte solution may pass from the frame of a frame plateassembly to a cell plate of the frame plate assembly, and then toanother frame plate assembly, and then ultimately to an electrolytereservoir.

FIG. 3A illustrates an example catholyte pathway between multiple frameplate assemblies of a redox cell stack 300. In aspects of thetechnology, a catholyte solution 302 enters a first frame plate assembly304.

The first frame plate assembly 304 may have a frame with a variety ofchannels, vias, membranes, porous material, and/or pathways to directthe flow of the catholyte solution 302 across a portion of the backsideof the first frame plate assembly 304. In aspects, flow may be directedthrough a frame of the first frame plate assembly 304 into a cellportion of the first frame plate assembly 306. In aspects of thetechnology, flow into the cell portion of the first frame plate assembly304 is directed across a backside of the membrane of the cell portion ofthe first frame plate assembly 304. Flow of the catholyte solution maybe directed such that a laminar sheet-flow occurs across the backside ofa membrane of a cell portion of the first frame plate assembly 304.

The catholyte solution 302 then proceeds to enter a second frame plateassembly 306. In aspects of the technology, the frame of the secondframe plate assembly includes channels, vias, membranes, porousmaterials, and or/pathways to direct the flow of the catholyte solution302 across a portion of a backside of the second frame plate assembly.Flow of 302 may enter and exit the frame plate assembly 306 in a similarmanner as frame plate assembly 304. In aspects, flow may be directedthrough a frame of the second frame plate assembly 306 into a cellportion of the second frame plate assembly. In aspects of thetechnology, flow into the cell portion of the second frame plateassembly 306 is directed across a backside of the membrane of the cellportion of the second frame plate assembly 306. Flow of the catholytesolution 302 may be directed such that a laminar sheet-flow occursacross the backside of a membrane of the cell portion of the secondframe plate assembly 306.

This pattern of flow of the catholyte solution 302 may proceed to aplurality of other frame plate assemblies, including a third frame plateassembly 308, and/or to a reservoir. Flow of 302 may enter and exit theframe plate assembly 308 in a similar manner as frame plate assembly304. In aspects of the technology, the catholyte solution 302 enters aframe plate assembly and flow may be directed such that the catholytesolution flows down a backside portion of the membrane of a cell portionof a plate assembly.

Illustrated in FIG. 3B is a flow of an anolyte solution 310. An anolytesolution may travel from a first frame plate assembly 304 to the secondframe plate assembly 306. The second frame plate assembly 306 may have aframe with a variety of channels, vias, membranes, porous material,and/or pathways to direct the flow of the anolyte solution 310 across aportion of the front side of the second frame plate assembly 306. Inaspects, flow may be directed through a frame of the second frame plateassembly 306 into a cell portion of the second frame plate assembly 306.In aspects of the technology, flow into the cell portion of the secondframe plate assembly 306 is directed across a front side of the membraneof the cell portion of the second frame plate assembly 306. Flow of theanolyte solution 310 may be directed such that a laminar sheet flowoccurs across the front side of the membrane of the cell portion of thesecond frame plate assembly 306.

The anolyte solution 310 then proceeds to enter a third frame plateassembly 308. Flow of the anolyte solution 310 may enter and exit theframe plate assembly 308 in a similar manner as frame plate assembly304. In aspects of the technology, the frame of the third frame plateassembly 308 includes channels, vias, membranes, porous materials, andor/pathways to direct the flow of the anolyte solution 310 across afront side of the third frame plate assembly 308. In aspects, flow maybe directed through a frame of the third frame plate assembly 306 in acell portion of the third frame plate assembly 308. In aspects of thetechnology, flow into the cell portion of the third frame plate assembly308 is directed across a front side of the membrane of the cell portionof the third frame plate assembly 308. Flow of the anolyte solution 310may be directed such that a laminar sheet flow occurs across the frontside of a membrane of the cell portion of the third frame plate assembly308.

This pattern of flow of the anolyte solution 310 may proceed to aplurality of other frame plate assemblies and/or to a reservoir. Inaspects of the technology, the anolyte solution 310 enters a frame plateassembly and flow may be directed such that the anolyte solution flowsdown a backside portion of the membrane.

In aspects of the technology, the electrolyte solutions flow to eachcell plate in a stack through a shared manifold. That is, in an example,each cell includes a flow path that enables an electrolyte to flow froman inlet to an outlet, and each frame plate assembly has an internalmanifold insert, such as electrolyte piping 226 and 224. Thus, stackingmultiple frame plate assemblies may create a common supply and returnmanifolds via the electrolyte piping. This internal manifold suppliesand returns electrolyte to the individual cells in a parallel flowconfiguration, in example embodiments. Other configurations arecontemplated.

FIG. 4 illustrates a perspective view of an example of a frame plateassembly 400 with a co-molded cell-plate 400 and co-molded framechannels 408. The dashed lines indicate where components are present,though not necessarily visible. For example, a dashed lined may indicatethat a component of a frame-plate assembly, such as the electrolytepathway, is integrated within the frame body 402. As illustrated, theframe 400 has a frame body 402 that is a rectangular prism.

Additionally illustrated are electrolyte pathways 408. Electrolytepathways 408 fluidically couple an electrolyte reservoir and/or otherframe plate assemblies to the frame 400. For example, one or more of theelectrolyte pathways 408 may be a catholyte supply pathway that deliversa catholyte solution to a cell plate, a catholyte return pathway thatreturns a catholyte solution to a catholyte reservoir and/or other frameplate assemblies, an anolyte supply pathway that delivers an anolytesolution to a cell plate, and/or an anolyte return pathway that returnsan anolyte solution to an anolyte reservoir and/or other frame plateassemblies. As illustrated, the electrolyte pathways 408 are dottedlines, indicating that they are present, though not visible, in theperspective view illustrated. The electrolyte pathways 408 may be formedthrough a variety of means, including tubing inserts, overmolding, lostwax, or a gas assist.

The electrolyte pathways 408 each have a frame channel end 410 and acell end 412. The frame channel end 410 fluidically couples theelectrolyte pathways 408 to a frame channel 414. The frame channel end410 may be an orifice that allows an electrolyte solution to flow fromthe frame channel 414 into an electrolyte pathway 408. Other structuralitems that allow the electrolyte pathways 408 to be in fluidiccommunication with a reservoir and/or other frame plate assemblies arecontemplated. As illustrated, the frame channel 414 is a component thathas been overmolded within the frame body 402 to form a unitaryconstruction with the frame. For example, the edges 413 of the framechannel insert are illustrated by a dashed line, indicating that theframe channel insert has been over molded. Similarly, the cell end 412fluidically couples the electrolyte pathway 408 to a cell plate 502.

Additionally illustrated is a cell plate 502. As illustrated, the cellplate 502 is rectangular prism. The edges of the cell plate 502 areindicated by dashed lines 405, indicating that the edges of the cellplate have been covered, such that at least a portion of the front face407 of the cell plated 502 is covered by the frame body 402. Asillustrated, the at least a portion is the perimeter of the cell plate502. In examples, the portion includes a portion defined by the edges405 of the cell plate 502.

The frame body 402 may be of a unitary construction. In aspects of thetechnology, the frame body 402 is a rectangular prism that is 18.5inches in width (x), 18.5 inches in length (y), and 0.5 inches inthickness (z). The frame body 402 may be molded of electricallyisolating and heat conducting materials, such as a thermally insulatingplastic. The frame body 402 may have a cell plate area in which toreceive the cell plate 502. The opening may be formed by cutting away aninner section of the frame body 402. In aspects of the technology theopening may be a rectangular in shape so as to accommodate the cellplate 502 that is rectangular in shape, though it need not be.Subsequently, the cell plate 502 may be placed into the opening inpreparation to overmold the cell plate into the frame. In other aspects,the opening may be formed during molding of the frame body 402.

With reference to FIG. 5, the frame channels 414A, 414B, 414C, and 414Dserve to deliver (or return) electrolytes from (or to) a reservoir, suchas the reservoirs described with reference to FIG. 1, to a cell plate(e.g., cell plate 502), and/or to adjacent frame plate assemblies withina cell stack. In aspects of the technology, the frame channels 414A,414B, 414C, and 414D form a tube or channel throughout a plurality offrame plate assemblies within a frame plate assembly. That is, eachframe channel may be coupled to another electrolyte frame channel of anadjacent frame to form a tube, pathway, or channel. In aspects of thetechnology, the frame channels 414A, 414B, 414C, 414D, and/or cell plateare integrated using a joining method. For example, frame channel 414Amay be joined to the frame body 402 using a joining material thatchemically bonds the edges of a component frame channel to the framebody 402. It will be appreciated that the frame channels 414A, 414B,414C, and 414D may be formed using the overmolding method as describedin further detail below.

In an embodiment of the technology, an electrolyte (such as an anolytesolution or a catholyte solution) may pass from a frame channel 414Athrough an electrolyte supply pathway 408A to a cell plate 502.Similarly, the opposite charged solution (such as a catholyte solutionor an anolyte solution) may enter through frame channel 414B. Theopposite charged solution may pass through the electrolyte supplychannel 408B to the cell plate 502. An electrolyte return pathway 408Cmay deliver an electrolyte solution (such as a catholyte solution or ananolyte solution) from the cell plate 502 to frame channel 414C, and onto another frame plate or to a reservoir. Similarly, another integratedelectrolyte return pathway 408D returns the opposite electrolytesolution (such as an anolyte solution or a catholyte solution) from thecell plate 502 to frame channel 414C and then on to another floatingframe plate assembly or to a reservoir.

The electrolyte supply pathways 408A, 408B, 408C, and 408D may be formedin a variety of ways. In one embodiment, tubing made of material that issubstantially inert to the electrolytes are used. An overmoldingtechnique may be used, as provided in further detail below. Where theelectrolyte comprises vanadium ions, poly-vinyl chloride, high densitypolyurethane, and/or polypropylene tubing may be used. In other aspectsof the technology, thermal molding or gas assist may be used may be usedon the frame body 402 to form one or more of the electrolyte pathways408A, 408B, 408C, and 408D.

As illustrated, joining members 512A, 512B, 512C, and 512D may couplethe electrolyte pathways 408A, 408B, 408C, and 408D to the cell plate502, respectively. The joining members may be overmolded during theovermolded processes. As illustrated, the joining member 512Afluidically couples the electrolyte supply pathway 408A to theovermolded cell plate 502 such that the frame channel 414A is in fluidiccommunication with the overmolded cell plate 502. Similarly, the joiningmembers 512B, 512C, and 512D fluidically couple the electrolyte pathways408B, 408C, and 408D to the cell plate 502, respectively. In aspects ofthe technology, the joining members 512A, 512B, 512C, and 512D are eachnipples made of high density polyethylene.

Additionally, or alternatively, the joining member may be tubing with apress fit, snap fit, threaded connection or other connection such thatthe joining resiliently engages with a cell plate. Further, the cellplate 502 may have a receiving element adapted to receive a press fit,snap fit, threaded connection or other connection. Inadditional/alternative embodiments, the joining member may be tubinghaving any number of flanges that extend radially out from the tubingsuch that the nipple resiliently engages with the inner surface of theorifice of a cell plate. In aspects, the joining member forms robustcoupling with a cell plate. Additionally, the joining member may beincorporated into the cell end of the electrolyte pathways 408A, 408B,408C, and 408D.

FIG. 6 illustrates a view of a face of an overmolded frame plateassembly 600 with electrolyte pathways 608A, 608B, 608C, and 608D. Itwill be appreciated that elements of FIG. 6 that are like numbered aselements previously discussed herein have the same or similar propertiesas those like numbered elements. As illustrated, overmolded integratedframe plate assembly 600 includes an overmolded cell plate 502, a framebody 402, bores 418, overmolded frame channels 414, and overmoldedjoining members 512A, 512B, 512C, and 512D.

Overmolded electrolyte pathways 608A, 608B, 608C, and 608D areillustrated. In aspects of the technology, a catholyte or electrolytesolution passes through the overmolded frame channels 414A, 414B, 414C,and 414D and then proceeds to the overmolded electrolyte pathways 608A,608B, 608C, and 608D, respectively. It will be appreciated thatovermolded electrolyte pathways may have similar properties as thosedescribe with respect to electrolyte pathways 408A, 408B, 408C, and408D. Additionally, in aspects of the technology, the electrolytesolution traverses a specified length of the overmolded electrolytepathways (e.g., electrolyte pathways 608A, 608B, 608C, and 608D) priorto entering the cell plate 502. The length of path may be tuned to aspecific electrical resistance and fluid resistance ratio. For example,in certain applications, it may be desirous to increase electricalresistance to prevent currents within an overmolded frame plate assembly600 and/or across frame plate assemblies within a cell stack.Additionally, for certain applications, it may be desirous to decreasefluid resistance within an overmolded frame plate assembly 600 and/oracross cell assemblies within a cell stack.

In aspects of the technology, electrical resistance is controlled bychanging various elements of the overmolded frame plate assembly 600.For example, the material of the overmolded electrolyte pathways, thelength of the electrolyte pathways, the size and shape of theelectrolyte pathways (e.g., diameter of the electrolyte pathways wherethe electrolyte pathways is a cylindrical tubing), the material, thesize, and the shape of a joining member, and the material, size, andshape of the frame channel nipples (e.g., frame channel nipples 620A,620B, 620C, and 620D) may alter the electrical resistance in thefloating frame plate assembly 600.

Similarly, the fluid flow resistance may be controlled by changingvarious elements of the overmolded frame plate assembly 600. Forexample, the material of the electrolyte pathways, the length of theelectrolyte pathways, the size (e.g., diameter of the electrolytepathways where the electrolyte pathways is a cylindrical tubing) andshape (e.g., a electrolyte pathways with an oval cross-section, arectangular cross section, a circular cross section) of the electrolytepathways, the material, the size, and the shape of a joining members512, and the material, size, and shape of the frame channel nipples 620may alter the fluidic resistance in the floating frame plate assembly600.

In an embodiment of the technology, the material of the overmoldedelectrolyte pathways 608A, 608B, 608C, and 608D is one of poly-vinylchloride, high density polyurethane, or polypropylene. In embodiments,the electrolyte path may be tubular in shape having a defined length anddiameter.

As illustrated, overmolded electrolyte pathways 608A, 608B, 608C, and608D take a corkscrew path around an overmolded integrated cell plate502, though it need not take such a path. Rather, the electrolytepathways may take a variety of paths, which may be designed toincrease/decrease electrical resistance while decreasing/increasingfluidic resistance. For example, a variety of bends, curves, etc. may bedesigned to alter the fluid resistance and/or the electrical resistancethat an electrolyte solution is subject to during flow within and/orthrough the floating frame plate assembly 600.

FIG. 7 is a perspective view of an overmolded frame plate assembly 700.It will be appreciated that elements of FIG. 7 that are like numbered asthose elements previously discussed herein have the same or similarproperties as those like numbered elements. As illustrated, anovermolded frame plate assembly 700 includes an overmolded cell plate502, overmolded frame channels 414A, 414B, 414C, and 414D a frame body402, electrolyte pathways 608A, 608B, 608C, and 608D and bores 418.

FIG. 7 also illustrates a first horizontal axis 702, a second horizontalaxis 704, and a vertical axis 706. A pitch angle 708, a roll angle 710,and a yaw angle 712 are also illustrated. In embodiments, the firsthorizontal axis 702 is an axis that extends radially out from a firstside wall 714 of the floating frame plate assembly 700 and is parallelto the front face 716 of the floating frame plate assembly 700.Additionally, in embodiments, the second horizontal axis 704 extendsradially from the second side wall 718 and is orthogonal to the firsthorizontal axis 702. Further, in embodiments, the vertical axis 706extends orthogonally outwards from the front face 716 of the overmoldedframe plate assembly 700.

In aspects of the technology, the cell-frame overmold material 517 mayallow the cell plate 502 to move independently from the frame body 402.Such independent movement allows for, in embodiments, the frame body 402to be manufactured thinner and manufactured less precisely with respectto flatness and thickness. That is, because the cell plates sealtogether, the manufacturing tolerances on the sealing elements of eachcell plate in a plurality of cell plates must, in embodiments, besufficiently high to reduce leaking of the electrolyte fluid. Decouplingthe movement of the frame body 402 from the cell plate 502 allows forthe frame body to locate and orient a cell on framing members whilereducing or preventing the frame body from interfering with a cellsealing with an adjacent cell.

For example, the cell-frame overmold material 517 may allow the cellplate 502 to rotate about the first horizontal axis 702 up to a pitchangle 708 of between +/−1 degree while the frame body 402 maintains apitch angle of 0 degrees. Additionally, the cell-frame overmold material517 may allow the cell plate 502 to rotate about the second horizontalaxis 704 up to a roll angle 710 of between +/−1 degree while the framebody 402 maintains a pitch angle of 0 degrees. Additionally, thecell-frame overmold material 517 may allow the cell plate 502 to rotateabout the vertical axis 706 up to a yaw angle 712 of between +/−1degrees while the frame body 402 maintains a pitch angle of 0 degrees.In other aspects, the degree angle may be greater. For example, thedegree angle of each angle of rotation may be +/−3. This may occurbecause the cell-frame overmold material is more flexible/elastic thanthe cell plate 502 and/or the frame body 402.

Similarly, the channel-frame overmold material 403 may allow the framechannel (414A, 414B, 414C, and/or 414D, for example) to moveindependently from the frame body 402. Such independent movement allowsfor, in embodiments, the frame body 402 to be manufactured thinner andless precisely with respect to flatness and thickness. That is, becausethe frame channels seal together, the manufacturing tolerances on thesealing elements of each frame channel in a plurality of frame channelsmust, in embodiments, be sufficiently high to reduce leaking of theelectrolyte fluid. Decoupling the movement of the frame body 402 fromthe frame channels allows for the frame body 402 to locate and orient acell on framing members while reducing or preventing the frame body frominterfering with frame channel sealing. This may occur because thechannel-frame overmold material is more flexible/elastic than the framechannel inserts and/or the frame body 402.

For example, the channel-frame overmold material 403 may allow the framechannel 414A to rotate about the first horizontal axis 702 up to a pitchangle 708 of between +/−1 degree while the frame body 402 maintains apitch angle of 0 degrees. Additionally, the channel-frame overmoldmaterial 403 may allow the frame channel 414A to rotate about the secondhorizontal axis 704 up to a roll angle 710 of between +/−1 degree whilethe frame body 402 maintains a pitch angle of 0 degrees. Additionally,the channel-frame overmold material 403 may allow the frame channel 414Ato rotate about the vertical axis 706 up to a yaw angle 712 of between+/−1 degrees while the frame body 402 maintains a pitch angle of 0degrees. In other aspects, the degree angle may be greater. For example,the degree angle of each angle of rotation may be +/−3. It will beappreciated that overmolded frame channels 414B, 414C, and 414D may havethe same or similar properties.

FIG. 8 illustrates a perspective view of an overmolded frame plateassembly 800. It will be appreciated that elements of FIG. 8 that arelike numbered as those elements previously discussed herein have thesame or similar properties as those like numbered elements. Asillustrated, overmolded frame plate assembly 800 includes an overmoldedcell plate 502, overmolded frame channels 414, and a frame body 402.

A frame body flatness 802, a frame channel component flatness 806, and acell plate flatness 804 are illustrated. A frame body flatness 802measures the flatness of a frame body from one point of a frame body toanother. As illustrated, the frame body flatness 802 is measured fromone side of a face of the frame body 402 (which, as illustrated is arectangular prism) to an opposite side on the same face of the framebody. Flatness may be described in millimeters of change in heightversus millimeters of change in length. In aspects of the technology,the frame body may be manufactured to have a flatness 802 of greaterthan 0.005″ per linear 1″. In alternative embodiments, the frame bodyflatness 802 may have a flatness of greater than 0.005 mm per 1 mm.

Additionally illustrated is cell plate flatness 804, which measures theflatness of a cell from one point of a frame to another. As illustrated,the flatness is measured from one corner of a face of the cell plate 502(which, as illustrated is a rectangular prism) to an opposite corner onthe same face of the cell plate 502. Flatness may be described inmillimeters of change in height versus millimeters of change in length.In aspects of the technology, the cell may be manufactured to have aflatness of at least 0.0005″ per linear 1″. In alternative/additionalembodiments, the flatness may be at least 0.0005 mm per 1 mm.

Additionally illustrated is a frame channel component flatness 806,which measures the flatness of a frame channel component from one pointof the component to another. As illustrated, the flatness is measuredfrom one corner of the frame channel 414 to an opposite corner on thesame face of the frame channel 414. Flatness may be described inmillimeters of change in height versus millimeters of change in length.In aspects of the technology, the frame channel component flatness 806may be manufactured to have a flatness of at least 0.0005″ per linear1″. In alternative/additional embodiments, the flatness may be at least0.0005 mm per 1 mm.

It will be appreciated that the choice of overmold material, such ascell-frame overmold material 517 described above, allows a plurality ofcell or channels with a certain flatness tolerance to be coupledtogether, while the frames of each of the plurality of cells or channelsmay be maintained at a lower flatness tolerance.

Fig. is a method 900 for overmolding a component into a frame plateassembly. The process 900 includes operation 902, which involvesproviding an overmolding component. In aspects of the technology, theovermolding component may be one of a frame channel insert, anelectrolyte pathway, or a cell plate as described herein. For example,the overmolded may be made via casting or another process.

The operation then proceeds to operation 904 may further involvearranging one or more overmolding component. One arrangement isdescribed with reference to FIG. 10. Four overmolding components 1000A,1000B, 1000C, 1000D are illustrated in FIG. 10. The particularovermolding components are illustrated as having similar characteristicsas those with respect to FIGS. 4-6 and/or 19-22, though they need nothave such characteristics. In aspects of the technology, the overmoldingcomponents include frame channel portions 1002A, 1002B, 1002C, 1002Dfluidically coupled to respective electrolyte pathway portions 1004A,1004B, 1004C, 1004D. The obtained overmolding components 1000A, 1000B,1000C, 1000D may be arranged in desired configuration, such as theconfiguration that the components will take in the frame. One or moreportions of the obtained overmolded components 1000A, 1000B, 1000C,1000D may be prepared to act as a substrate for an overmolding process.This may involve, for example, cleaning, treating, or otherwisepreparing the overmolded components 1000A, 1000B, 1000C, 1000D forovermolding.

Returning to FIG. 9, after the one or more overmolding components areprovided, the process 900 may move to identify substrate operation 906.In aspects, a substrate may be a rectangular prism. In other aspects,the rectangular prism may have cutaways such that the overmoldedcomponents may insert into the substrate (an example of such anarrangement is provided in FIG. 14 as frame body 2008. The one or moreovermolding components may be placed on a substrate, such as a semirigidor rigid of rectangular prism for form an overmold assembly. Theovermold assembly may then be placed within a mold or other apparatusoperable to overmold the substrate.

Operation 900 then proceeds to overmold operation 906. Overmolding mayoccur via a variety of means, including plastic injection molding orsome other means. The apparatus may then be used to mold a frame (e.g.,frame 400) to join the overmolding components. The overmold assemblymay, but need not, be overmolded using different materials (i.e., theovermold material) from the overmolding component and/or substrate. Inan example, the overmolding components may be made from a relativelyinflexible material (e.g., inflexible resins, plastics, graphite, etc.),while the frame may be overmolded using a flexible material to provideoverall tolerance (e.g., float) to the resulting frame assembly. Afterthe overmolding process occurs, an area for the cell plate and/or holesadapted to receive framing members may be bored out.

FIG. 11 illustrates an example of the result of the overmold assemblyhas been overmolded. As illustrated, FIG. 11 includes frame channelportions 1002A, 1002B, 1002C, 1002D fluidically coupled to respectiveelectrolyte pathway portions 1004A, 1004B, 1004C, 1004D. The obtainedovermolding components 1000A, 1000B, 1000C, 1000D may be arranged asshown on a substrate 1102. As illustrated, bores 1114 and cell-platearea 1118 are adapted to receive a cell and framing membersrespectively.

Operation 900 then optionally proceeds to overmold cell operation 908.In operation 908, a cell plate is placed within the cell plate area 1118to form a cell-plate overmold assembly. The overmold cell-plate assemblymay then be overmolded via plastic injection method or another method.

FIG. 12 illustrates an example embodiment of a frame plate assembly 1200that includes an overmolded cell plate 502. In aspects, this may beformed using the method described in operation 908. For example,following the overmolding of overmold-assembly of FIG. 11, a cell plate502 may be inserted in the cell-plate area 1118 and coupled to theelectrolyte pathways 1004A, 1004B, 1004C, 1004D. The frame 1120 and thecell plate 502 may then be used as a substrate for an overmoldingprocess that applies an overmolding material over the cell plate 502.The dashed lined 1202 indicates the edge of the cell plate, which is nownot visible and is embedded in the body of the resulting frame-plateassembly. The overmolding material may robustly seal the connectionbetween the cell plate 502 and the electrolyte pathways 1004A, 1004B,1004C, 1004D without the need for additional sealing components, such aO-rings. In some examples, the overmolding material 1204 may contributeto an overall float of the cell plate 502 relative to the frame 1120.

FIG. 13 illustrates a perspective view of a cell plate 1900, which maybe overmolded into a frame plate assembly. In aspects of the technology,the cell plate 1900 includes a first orifice 1902, a second orifice1904, a third orifice 1906, and a fourth orifice 1908. As illustratedthe first orifice 1902, the second orifice 1904, the third orifice 1906,and the fourth orifice 1908 are circular in shape. In aspects of thetechnology, the orifice may be adapted to receive a joining member, suchas the joining members described herein. For example, where the joiningmember is threaded, the first orifice may have threads about an innerannular surface. Where the joining member is a cylindrical tube ornipple and has a number of flanges extending radially outward from thecylinder, the inner annular surface may have a corresponding ridge,which may receive the flanges of the cylindrical tubing or nipple.Additionally or alternatively, the nipple of the joining member may betapered such that the joining member may be insertably removed from anorifice, such as a first orifice 1902.

As illustrated, the cell plate is a rectangular prism with a front faceand a back face. The cell plate may be coupled to a redox flow batterythrough the use of joining members. For example, a joining member maycouple to an orifice, such as the first orifice 1902, the second orifice1904, the third orifice 1906, and the forth orifice 1908, andfluidically couple the cell plate 1900 to an electrolyte reservoir andor other cells within a cell stack.

In aspects of the technology, the cell plate 1900 includes one or moreheat exchange elements. For example, a first heat exchange element 1910may be coupled to a first wall 1918, a second heat exchange element 1912may be coupled to a second wall 1920, a third heat exchange element 1914may be coupled to a third wall 1922, and a fourth heat exchange element1916 may be coupled to a fourth wall 1924. As illustrated, the heatexchange element is a fin that protrudes from a wall and runslength-wise along the wall. In other embodiments, the heat exchangeelement may be a series of teeth or other structure that aids indissipating heat from the cell plate 1900.

FIG. 14 illustrates an exploded view of an embodiment of a frame plateassembly 2000 with various components that may, in aspects, beovermolded. As illustrated, FIG. 14 includes overmold component members2002A, 2002B, 2002C, and 2002D. It will be appreciated that elements ofFIG. 14 having like numbered as elements previously described will havethe same or similar properties as those like numbered elements. Asillustrated, the frame plate assembly 2000 includes a cell plate 502,joining members 512A, 512B, 512C, and 512D, a frame body 402, andovermold component electrolyte pathways 608A, 608B, 608C, and 608D.

Additionally illustrated are overmolded components 2002A, 2002B, 2002C,and 2002D. The overmold components 2002A, 2002B, 2002C, and 2002D may beplaced into the frame channel area 2004A, 2004B, 2004C, and 2004D of theframe body 2008 in preparation for overmolding. As illustrated, each ofthe overmolded components 2002A, 2002B, 2002C, and 2002D is arectangular prism, though they need not be. For example, othergeometries are contemplated, including cylindrical shapes.

In aspects of the technology, the overmolded components 2002A, 2002B,2002C, and 2002D and the frame channel area 2004A, 2004B, 2004C, and2004D form all or a part of a frame channel when the overmoldedcomponents 2002A, 2002B, 2002C, and 2002D are inserted into theirrespective frame channel areas and overmolded.

Examples of overmolded components 2002A, 2002B, 2002C, and 2002D arediscussed further with reference to FIGS. 15A-15D.

FIGS. 15A-15D illustrate various views of an embodiment of frame channelovermolded components. In particular, FIG. 15A, FIG. 15B, FIG. 15C, andFIG. 15D illustrate a front, side, perspective, and back view of a framechannel overmolded component is a radial connector insert 2100,respectively. A radial connector insert 2100 may be used to allow anelectrolyte solution to flow from one frame channel of a first frameplate assembly to a second frame channel of an adjacent, second frameplate assembly. Additionally, the radial connector insert 2100 includesa connection element 2102 which, in operation, fluidically couples acell of the frame plate assembly to other frame plate assemblies and/oran electrolyte reservoir. As illustrated, radial connector insert 2100includes a rectangular prism insert body 2103. In other aspects, thebody 2103 may be a different shape.

As illustrated, the radial connector insert 2100 has an opening 2110that allows, in aspects, an electrolyte to flow from one frame plateassembly to another frame plate assembly and/or to an electrolytereservoir. Indeed, each radial connector insert 2100 may have a sealingelement 2112 that protrudes from a front face 2114 of the radialconnector insert 2100 and may be adapted to couple to a back face 2116of an adjacent frame channel component. As illustrated, the sealingelement 2112 protrusion is defined by a perimeter of the opening 2110.The protrusion has a face 2118 that may be substantially planar. In someaspects, the face 2118 of the sealing element 2112 may couple to anO-ring or other material to aid in forming a robust seal with anadjacent frame channel.

An attachment element 2120 may correspond to a receiving element of aframe, such as the frame described with reference to FIG. 14. Forexample, an attachment element 2120 may be a tongue that protrudes froma side wall of the radial connector insert 2100 and inserts into a slotof the frame. In other aspects, other attachment elements may be used,such as snap fittings. This may allow the radial connector insert 2100to be removably inserted into the frame body of a frame plate. This mayaid in keeping the overmold component in place during over molding.

Additionally illustrated is a connection element 2102. As illustrated,the connection element 2102 extends orthogonally from the first wall2122 of the body 2103. In aspects of the technology, the connectionelement 2102 may be a tube with a press fit, snap fit, threadedconnection or other connection such that the connection elementresiliently engages with a frame end of an electrolyte pathway, such asan anolyte or catholyte pathway described with more detail above. Inaspects, this allows the frame channel to be in fluidic communicationwith one or more cell plates. For example, in aspects, the connectionelement 2102 has a pathway 2124 that fluidically couples the opening2110 to a cell of a frame plate assembly when in operation.Specifically, the opening 2110 may be defined by an annular wall 2126.Additionally, the pathway 2124 may be through the body 2103 to openingon the annular wall 2126.

FIGS. 16A-16D illustrate various views of an embodiment of an overmoldedcomponent. In particular, FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16Dillustrate a front, side, perspective, and back view of an overmoldedcomponent that is a radial spacer insert 2200. A radial spacer insert2200 may be used to allow an electrolyte solution to flow from one framechannel of a first frame plate assembly to a second frame channel of asecond frame plate assembly. As illustrated, a radial spacer insert 2200includes a rectangular prism insert body 2202. In other aspects, thebody 2202 may be a different shape.

As illustrated, the radial spacer insert 2200 has an opening 2210 thatallows, in aspects, an electrolyte to flow from one frame plate assemblyto another, adjacent frame plate assembly. Indeed, a radial spacerinsert 2200 may have a sealing element 2212 that protrudes from a frontface 2214 of the radial spacer insert 2200 and may be adapted to coupleto a back face 2216 of another overmolded component. As illustrated, thesealing element is a protrusion, which protrusion is defined by aperimeter of the opening 2210. The protrusion has a face 2218 that maybe substantially planar. In some aspects, the face 2218 of the sealingelement 2212 may couple to an O-ring or other material to aid in forminga robust seal with an adjacent frame channel.

An attachment element 2220 may correspond to a receiving element of aframe, such as the frame described with reference to FIG. 14. Forexample, an attachment element 2220 may be a tongue that protrudes froma side wall and inserts into a slot of the frame. In other aspects,other attachment elements may be used, such as snap fittings. This mayallow the radial spacer insert to be insertably removable into the framebody of a frame plate. In some aspects, this may allow for theovermolded component to be held in place during the overmolding process.

Frame plate assemblies (e.g., frame plate assembly 502), componentsthereof, and other aspects of technologies described herein may becreated in a variety of manners. In an embodiment, the pathways of aflow battery (e.g., electrolyte pathway 608) are made from tubing placedinto spaces in a frame. For instance, the frame may include channels,troughs, conduit hangers, or other components for holding tubingrelative to the frame. The tubing or other electrolyte pathways may beseparate from and connectable to frame channel members that fluidicallycouple the frame plate assembly to other frame plate assemblies and/oran electrolyte reservoir (e.g., radial connector insert 2200). Thepathways may facilitate transport of fluid from the frame channelmembers to a cell plate (e.g., cell plate 502) of the frame plate.Connections may be made between the pathways and the frame channelmembers using any of a variety of connection mechanisms, and O-rings (orother sealing components) may be used to facilitate a seal between thecomponents.

The description and illustration of one or more embodiments provided inthis application are not intended to limit or restrict the scope of theinvention as claimed in any way. The embodiments, examples, and detailsprovided in this application are considered sufficient to conveypossession and enable others to make and use the best mode of claimedinvention. The claimed invention should not be construed as beinglimited to any embodiment, example, or detail provided in thisapplication. Regardless of whether shown and described in combination orseparately, the various features (both structural and methodological)are intended to be selectively included or omitted to produce anembodiment with a particular set of features. Having been provided withthe description and illustration of the present application, one skilledin the art may envision variations, modifications, and alternateembodiments falling within the spirit of the broader aspects of thegeneral inventive concept embodied in this application that do notdepart from the broader scope of the claimed invention.

What is claimed is:
 1. A frame plate assembly comprising: a frame havinga frame body made of frame body material; a plurality of electrolytepathways disposed within the body; a plurality of joining members,wherein the plurality of electrolyte pathways couple to a cell plate viathe joining members, which are configured to extend at least partiallywithin the plurality of electrolyte pathways and to fluidically couplethe plurality of electrolyte pathways to the cell plate; the cell platehaving a front face, wherein at least a portion of the front face hasbeen overmolded with the frame body material such that an overmoldingframe body material covers the plurality of joining members and at leasta portion of the front face and couples to the frame body; and whereinthe overmolding frame body material forms a seal between the cell plateand the plurality of the electrolyte pathways.
 2. The frame assembly ofclaim 1, wherein the portion is defined by a perimeter of the front faceof the cell plate.
 3. The frame plate assembly of claim 1, wherein theelectrolyte pathways are a tubular shape.
 4. The frame plate assembly ofclaim 1, wherein the overmolding frame body material allows the cellplate to rotate by at least 1 degree about an axis independently fromthe frame of the frame plate assembly.
 5. The frame plate assembly ofclaim 1, wherein the cell plate is more rigid than the overmolding framebody material.
 6. The frame plate assembly of claim 1, furthercomprising a cell plate flatness of 0.0005 millimeters per linear inch;and a frame plate flatness of 0.0005 inches per linear inch.
 7. Theframe plate assembly of claim 3, wherein each joining member comprises atubular member configured as a nipple or configured as a press fit, asnap fit or a threaded connection.
 8. The frame plate assembly of claim7, wherein each joining member resiliently engages with the cell plate.9. The frame plate assembly of claim 7, wherein the cell plate includesa plurality of receiving elements configured to receive the tubularjoining member.
 10. The frame plate assembly of claim 3, wherein eachjoining member comprises tubing configured as a nipple having one ormore flanges extending radially out from the tubing, the one or moreflanges configured to resiliently engage with an inner surface of anorifice of a cell plate.
 11. The frame plate assembly of claim 10,wherein each joining member includes plural flanges configured to bereceived by at least one corresponding ridge in an orifice of the cellplate.
 12. The frame plate assembly of claim 7, wherein each joiningmember includes a threaded surface configured to be received incorresponding threads of an inner annular surface of an electrolytepathway of the cell plate.
 13. The frame plate assembly of claim 3,wherein the plurality of joining members are incorporated into the cellend of the plurality of electrolyte pathways.